| Raymond Sadeghy
Research Assistant Professor
Office Phone:(210) 458-5747
Office: SB 3.01.28
Areas of Specialization
• Simulation of Chemical Reactions using Time-dependent wave packet propagator
using fast Fourier Transform (publications 1-5)
• Simulation of photodissociation Dynamics of CO2 in the upper
atmosphere using electronic structure calculation and
wave packet propagator simulators. The work involved collaborating with the experiments done at Brown University in Peter Weber's laboratories (publication 6)
• Simulation of Reaction in the bulk using Monte Carlo simulation
• Simulation of Reactions using Electron-Nuclear Dynamics for reaction of
electrons with gaseous oxygen, hydrogen
Theoretical Chemistry: Kinetics and Dynamics
The application of theoretical models to important problems in chemistry is the focus of my research program. Topics currently under study can be grouped into two broad categories: (1) small molecule chemical physics, and (2) collisional energy transfer between gas phase molecules. The typical Ph.D. thesis produced by students in my group will contain a mix of computer simulations, analytical modeling, and an analysis of experimental data. For all the projects presently underway, there is a strong emphasis on interfacing with state-of-the-art experimental work.
The process of translational, rotational, and vibrational energy interconversion during collisions remains a topic of great interest and not yet fully understood. Recent experiments on collional energy transfer between highly vibrationally excited molecules of azulene (C10H8) and krypton atoms have revealed results which are not replicated by the current available theoretical models that utilize a mixture of quantum mechanical calculations along with classical trajectory methods without a global potential energy surface. We shall develop a semiclassical wave packet method to approach the quantum dynamics and obtain the differential cross section.
In small molecule chemical physics, areas of particular interest include: theory of chemical reactions in the gas phase, and dynamics of molecular collisions. In the last few years, my strongest emphasis has been on transition state spectroscopy. This is due in no small part to the influx of new high-quality experimental results requiring interpretation. Recently, I have utilized the theory of END (Electron Nuclear Dynamics) to study chemical reactions at high energies. The simulations are motivated by recent experimental findings. END is a formulation of the complete dynamics of electrons and nuclei of a molecular system that eliminates the necessity of constructing potential energy surfaces which are computationally costly, and in most cases, implausible.
“Control of Transition State Spectra: Enhancement of Diffuse Structure in the Photodissociation Spectrum of CO2"
Sadeghi, R.; Skodje, R. T.;
J. Chem. Phys. 105, 7504 (1996).
“Quantum Dynamics at the Transition State: Spectral Quantization and Spectral Control applied to the FH2 Photodetachment Process"
Skodje, R. T.; Sadeghi, R.; and Krause, J. L.
J. Chem. Soc. Faraday Trans. 93, 765 (1997).
“Control of Transition State Spectra: A Variational Algorithm"
Skodje, R.T.; Sadeghi, R.; and Krause, J. L.
Chemical Physics 240 (1999) 129-139.
“Structure and Dynamics of the S3 State of CS2"
Sadeghi, R.; Krause,
J. L.; Skodje, R. T.
J. Chem. Phys. 107, 6570 (1997).
“The Dynamics of Proton Transfer in a Water Chain"
Sadeghi, R.; Cheng,
J. Chem. Phys. 111, 2086 (2000).
“Coherent State Dynamics of H+ + HF reaction at Elab=30 eV”
Maiti, B., Sadeghi, R. Morales, J.
Chem. Phys. 340, 105 (2007).
“Exploring H+ + CF4 at Elab =20 and 30 eV”
Maiti, B., McLaurin, P, Sadeghi, R., Perera A, Morales, A.
Quantum Chem. Accepted for publication (2009)
“Dynamics of H+ + NO at Elab = 30 eV”
Manuscript in Preparation, To be submitted to Chem. Phys. Lett. (2009)
“Dynamics of H+ + CO at Elab = 30 eV”
Manuscript in Preparation, to be submitted to J. Phys. Chem. (2009)
“Time-dependent semiclassical approach to a highly activated complex molecule”
Sadeghi, R., In preparation.
Other relevant Information
• Developed a faster Data Base using Oracle 8i (Dell Inc., Austin, TX )
• Kinetic modeling of combustion of methane using Runge-Kutta and techniques in the field of non-linear dynamics. The experiments were done at Argonne National Laboratories where we obtained the necessary rate-constants required for the